Remote control installations for the valves of marine tankers



Jan. 30, 1962 v POMPE 3,018,628

R REMOTE CONTROL INSTALLATIONS FOR THE 1 VALVES OF MARINE TANKERS FiledDec. 16, 1958 2 Sheets-Sheet l lNVENTOR I VJcTor Povnrer BY XTm/Rfi YS'Jan. 30, 1962 v. POMPER REMOTE CONTROL INSTALLATIONS FOR THE VALVES OFMARINE TANKERS 2 Sheets-Sheet 2 Filed Dec. 16, 1958 /NVE/\/TOR Tor pmrer- BY ATTORN YS United States This invention relates to remotecontrol installations for the hydraulic operation of so-called freightvalves on marine tankers, used for emptying or syphoning out the tanks.

Such installations comprise a common source of liquid under pressure, ajack arranged in the vicinity of each valve and the movable member ofwhich is mechanically connected to the valve member of the correspondingvalve, a hydraulic control valve associated with each jack, and a devicefor indicating the movement or position of each valve member, thisdevice being constituted by a liquid flow indicator.

In order to improve these installations, according to the presentinvention, the jacks are double acting jacks, each hydraulic controlvalve being such that the liquid discharged from one or the other of theactive chambers of the corresponding jack by the displacements of thepiston of the latter passes through the same discharge conduit and thesaid liquid flow indicator is arranged in this conduit.

The invention is illustrated by way of example in the accompanyingdrawings in which:

FIGS. 1 and 2 diagrammatically illustrate in elevation and in planrespectively, a tanker equipped with an installation in accordance withthe invention.

FIG. 3 shows this installation in more detailed fashion with parts insection and parts in elevation.

In the drawings it is assumed that the installation according to theinvention is applied to the remote control of valves A A A and A (FIGS.1 and 2) of a tanker.

This installation comprises a hydraulic plant B which supplies oil underpressure and through as many control elements, such as C and C as thereare valves, such as A and A to be controlled (FIG. 3), the said controlelements being grouped at a control station D (FIG. 1). The valves, forexample A and A each comprise a body 1 and a valve member 2 which isrigid with the rod 3 of the piston 4 of a double-acting jack, the casing5 of which is fixed to the body of the valve 1, preferably above thelatter. A sealing packing 6 separates the jack from the valve. Thepiston 4 divides the jack cylinder into an upper chamber 7 and a lowerchamber 8.

The hydraulic plant B essentially comprises pumping means and pressureaccumulating means.

The pumping means comprise two motor pumps, one being the normallyworking pump, called service pump, and the other an emergency pump,having a common delivery conduit 12. If, for any reason, the servicepump ceases to work, the emergency pump is brought into action. Thesetwo motor pumps, each of which comprises an electric motor 9 and aconstant delivery pump 10, draw oil from a reservoir 11 and deliver itinto said conduit 12. The individual delivery lines of the two groups,and the common conduit 12, are provided with non-return valves 13'. Anadjustably-loaded valve 14 limits the delivery pressure of the pumpingmeans to a specific value P (for example 40 kg./cm.

The pressure accumulating means comprise a battery of accumulators eachcomprising a casing 15 enclosing a variable volume chamber 16 which isfilled with gas under pressure (for example nitrogen). The spaces,designated by 17, left in the casings 15 on the outside of thesechamatet bers 16 contain oil, and these spaces are connected in parallelto a conduit 18.

In this conduit 18 there is a valve 19 provided with a calibratedorifice 20 and urged by a spring 21 in a direction such that the flow ofoil leaving the accumulators is slowed down by the said orifice, throughwhich it is compelled to flow, whilst oil flowing toward theaccumulators pushes back the valve 19 against its spring 21 and thus isnot subjected to any braking.

The above mentioned conduits 12 and 18 are connected through a commonconduit 22 to the group of control elements, such as C and C A switch,advantageously an electric switch 23, located at the control station D,can be controlled by the operator so that, in a first position thereof(in dotted lines in FIG. 3) corresponding to the actuation of thevalves, the energizing circuit 24 of a solenoid valve 25 (FIG. 3) andthe energizing circuit 26 of the motor of the service pump are fed withcurrent and, in a second position corresponding to the holding of thevalves in position, the energizing circuit of said valve 25 is no longerfed with current and a secondary energizing circuit 27 of the said motor9 is fed with current.

The solenoid valve 25 is such that, when the switch 23 is in the abovestated first position, the conduit 18 and the accumulator means 1516 areshut oti, the service pump 10 then delivering oil continuously andslowly into the conduit 22 at the pressure set by the loading of valve14, and that, when the valve 23 is in the second position (illustratedby FIG. 3), the conduit 18 and the accumulator means 15-16 are connectedto the control elements such as C and C through the conduit 22, theservice pump 10 then intermittently feeding oil to the accumulator means15-46 and to the control elements when the secondary energizing circuit27 is in action.

This secondary energizing circuit is controlled by two pressure contacts28 and 29 which are subjected to the pressure prevailing in theaccumulator means, which is transmitted through a conduit 30, thecontact 28 starting the service motor 9 when this pressure falls below afirst limit value P (for example 25 kg./cm. and the contact 29 stoppingthis motor when this pressure exceeds a second and higher limit value P(30 kg./cm. for example), this second limit value being less than theloading pressure P of the valve 14.

A third pressure contact 31, which is loaded at a pressure P lower thanP and is arranged in parallel with the two others, may be provided toactuate a visual or audible alarm signal at the control station D incase of the pressure in the accumulators dropping below the pressure forwhich the contact 28 is 'set as the result of a failure in the operationof the service motor pump. This alarm signal will warn the operator thathe must bring the emergency motor pump into service.

Advantageously a hydraulic resistance 32, consisting for example of acoil of relatively narrow cross section, is provided in the conduit 30to prevent pressure fluctuations from operating the contacts 28, 29 and31.

The control elements, such as C and C each comprises a hydraulic slidevalve 33 the sliding member 34 of which is operated by a lever 35. Inone of the positions of this sliding member 34 (shown in solid lines inthe case of element C the slide valve 33 connects the conduit 22, whichis supplied with oil either at pressure P by the service pump 10 or at apressure between P and P by the accumulator means, with the upperchamber 7 of the jack of the corresponding valve through a conduit 36,and it also connects the lower chamber 8 of this jack through a conduit38 with a discharge conduit 37. In the other position of the slidingmember 34 (which has been shown partially in solid lines in the case ofthe element C the slide valve 33 connects the conduit 22 to the lowerchamber 8 of the jack through the conduit 38 and also connects the upperchamber 7 of the jack through a conduit 36 to the discharge conduit 37.

Of course, the location of the valves, such as A and A does not permitthe use of electrical limit contacts or equivalent means actuateddirectly by the moving parts 2, 3, 4. of the valve for indicatingcorrect operation of the valve, since the valves are disposed in thebottom of the holds several metres below the level of the crude oiltherein.

I provide correct operation indicator means which may be arranged at anysuitable place, in particular at the control station, advantageously byinserting a delivery meter in the discharge conduit 37. It will in factbe appreciated that oil is expelled from the jack into this dischargeconduit, either from the jack upper chamber 7 when the valve is openedor from the lower chamber 8 when the valve is closed, only when themoving parts 2, 3, 4 are actually displaced in response to the actuationof the corresponding lever 35.

A delivery meter of this nature comprises a cylinder 39, a piston 40movable therein, with calibrated orifices 41 extending from one side tothe other of said piston, this piston being urged in the downwarddirection by a spring 42, the rod 43 of this piston passing through thewall of the cylinder 39.

In the conduits 38 connecting each slide valve 33 with the lower chamber8 of the corresponding jack there is mounted a holding valve 44 whichpermits oil to flow from this chamber only when its pressure reaches orexceeds a predetermined limit value higher than that corresponding tothe weight of the moving parts 2, 3. 4 of the valve, this holding valvebeing connected in parallel with a non-return valve 45 allowing the oilto flow in the opposite direction to that first mentioned, that is tosay toward the chamber 8.

Advantageously the levers 35 are grouped in the control post D in aphysical arrangement reproducing that of the valves A A A and A asdiagrammatically illustrated in FIG. 2.

The installation above described operates as follows:

During the period of operation of one or more valves, the operatorplaces the electrical switch 23 into the Operate position, the result ofwhich is:

(l) The energizing of the solenoid valve 25, which shuts off theaccumulator means -16.

(2) The starting of the service motor pump 9-10.

The operator can now make use of the full delivery from the service pumpto open or close one or more valves, by moving the lever of thecorresponding slide valve or slide valves 33.

The valve opening or closing operations being completed, the operatorbrings the switch 23 into the Hold position, and the effect of this is:

(l) to de-energize the solenoid valve 25 and, as a result, to bring theaccumulators back into circuit,

(2) to place the motor pump under control of the pressure contacts 28and 29.

The accumulators therefore maintain in the hydraulic circuit a pressurebetween the limits P and P corresponding respectively to the loading ofthe pressure contacts 28 and 29.

Thus the accumulators constantly hold the valves in the open or closedposition, according to their own respective positions, as determined bythe operations which have previously occurred.

If the pressure in the accumulators falls to P as a result of leakagesin the system, the pressure contact 28 starts up the service motor pumpand this starts charging the accumulators.

As soon as the pressure in the accumulators reaches P the pressurecontact 29 stops the motor pump and the accumulators maintain thedesired pressure in the circuit.

Two electrical occurrences are possible:

(1) The contact 28 may not start the motor pump charging group, so thatthe pressure in the accumulators keeps dropping below P (2) The contact29 may not out 01f the supply current of the charging group, so that thepressure increases to P which is the calibrated pressure of thedischarge valve 14.

In the first instance, that is to say if the accumulators are notcharged despite the signal given by the pressure contact 28, when thepressure in the accumulators has dropped to P the pressure contact 31will operate a visible or audible signal. The operator will thus bewarned of the non-functioning of the service motor pump and will then bein a position to bring into operation the emergency motor pump, which inturn will charge the accumulators.

In the second instance, that is to say if the motor pump does not stopdespite the fact that the pressure P is reached in the accumulators, theincrease in pressure to the loading pressure P of the valve 14illuminates a visible signal, for example through special pressurecontact (not shown) which warns the operator of the danger of excessiveheating of the oil. The operator will then intervene and stop the motorpump by means of an electric press button.

The non-return valves 13 shut 06 the accumulators from the motor pumpsand from the discharge valve for the purpose of preventing possibleleakage when the pumps are stopped during actual operation. Thenonreturn valve 13 associated with the emergency group (at this time notin service) shuts off the latter.

When an operation is started, as soon as there is a movement of thepiston 4 in the jack of the remotely controlled valve, the dischargedliquid flows through the conduit 37 and meets a resistance during itspassage through the calibrated orifices 41 of the piston 40 of thedelivery meter 39. The pressure thus created on the side opposed to thespring 42 moves the piston upwardly, and the end of its rod 43 passesout of the body of the meter (into the position shown in dotted lines)and indicates to the operator that the oil is circulating, and thus thatthe movement of piston 4, and of the corresponding valve 2 is takingplace.

As soon as the piston 4 stops, the oil no longer circulates and thespring 42 retracts the rod 43 of the delivery meter, signalling the endof the operation. The pressure in the circuit then rises to P whichcorresponds to the loading of the discharge valve 14 and is selected soas to ensure liquid tight closure of the remotely controlled valve.

The holding valve 44 balances the weight of the moving parts of theremotely controlled valve so that the moving part of the valve ispositively actuated during the valve closing operation. The loading ofvalve 44 depends on the weight of the moving parts.

During the opening movement, the holding valve 44 is short circuited bythe non-return valve 45 which enables oil to flow freely toward thepiston 4 of the corresponding valve.

In a general manner, while I have, in the above description, disclosedwhat I deem to be practical and efficient embodiments of my invention,it should be well understood that I do not wish to be limited thereto asthere might be changes made in the arrangement, dis-- position and formof the parts without departing from the principle of the presentinvention as comprehended within the scope of the accompanying claims.

What I claim is:

1. A hydraulic remote control system which comprises, in combination, adouble acting hydraulic jack, said jack including parts forming twovariable volume chambers, so that expansion of one of said chambers andretraction of the other corresponds to operation of said jack in onedirection whereas retraction of said first mentioned chamber andexpansion of the other corresponds to operation of said jack in theopposed direction, a conduit starting respectively from each of said twochambers, a source of power liquid under pressure, a feed pipe leadingfrom said source, a discharge conduit, valve means interposed betweensaid two first mentioned conduits, said feed pipe and said dischargeconduit, said valve means being capable of connecting either of said twofirst mentioned conduits with said feed pipe and the other with saiddischarge conduit, and liquid flow indicator means inserted in saiddischarge conduit, said source of power liquid under pressure comprisingpumping means having the delivery thereof in communication With saidfeed pipe, accumulator means, a connecting conduit between said feedpipe and the delivery of said accumulator means, a valve in saidconnecting conduit for opening and closing the communication betweensaid feed pipe and said accumulator means, and electric motor fordriving said pumping means, an electric circuit comprising a source ofcurrent for operating said motor, electromagnet means for controllingsaid valve arranged, when energized, to place said valve in thecommunication closing position, said valve being in the communicationopening position when said electro-magnet means is not energized, .anelectric circuit including a current source for energizing saidelectromagnetic means, said two electric circuits having a portion incommon, and a switch in said electric circuit portion adapted, in afirst position thereof, to be used to operate the hydraulic jack, toclose both of said electric circuits and, in a second position thereof,to be used to keep said hydraulic jack in stationary position, to openboth of said electric circuits.

2. A remote control installation according to claim 1 further includingautomatic control means to start said pumping means into operation whenthe pressure in said feed pipe is between two given values, saidautomatic means being placed under control of said switch mechanism tobe operative only when said switch mechanism is in said second position.

References Cited in the file of this patent UNITED STATES PATENTS1,616,841 Beebe Feb. 8, 1927 2,239,481 Chistensen Apr. 22, 19412,243,074 Anderson May 27, 1941 2,253,617 Grifiith Aug. 26, 19412,322,517 Hose June 22, 1943 2,632,999 Balton Mar. 31, 1953 2,665,122Rowland Jan. 5, 1954 2,678,752 West May 18, 1954 2,748,569 Jackson June5, 1956 2,839,895 Hemeon June 24, 1958 2,888,029 Govan May 26, 1959

